Perinatal Lesions of Cerebral and Cerebellar Cortex

Abstract

Bresler (1889) reported pathologic observations in 2 mentally defective patients, both showing focal narrowing of cortical gyri on gross inspection of the brain. In the first case there was a cleft in the region of the left Sylvian fissure, communicating with the ventricle, and small convoluted gyri were abundant in both frontal and anterior parietal lobes. The second showed foci of small gyri in approximately symmetrical distribution, parasagittal in the central regions and in the occipital lobes. Microscopic examination of the first case revealed numerous minute gyri with a dense population of nerve cells and radial and transverse myelinated fibers. In the second case the cortex was absent at the bottom of the sulci; the gyri appeared pedunculated on long stalks, their crowns containing irregular islands of cortical tissue separated by zones of dense gliosis having affinity for myelin stains. The different characteristics of the small gyri in these cases were documented with gross and microscopic illustrations. Bresler compared his cases with others in the literature—in particular his second case with the one reported by Köppen (1896)—and concluded that the two types of gyral atrophy differed in principle. He proposed to call the first type microgyria, the second ulegyria (gyral scarring). He emphasized that ulegyria differed from microgyria in the extent of glial proliferation, indicating scar formation.